Cyclone Donna intensifies; lingers in Vanuatu's north

Cyclone Donna was upgraded to a category four on Saturday as it continued to batter Vanuatu's northern islands for a second day.

On Saturday night, the cyclone, which had been tracking west towards open ocean, turned around and continued to linger about 200 kilometres off the northernmost Torba province, where reports of damage were starting to emerge.

In a warning on Saturday night, the Vanuatu Meteorological Service said the cyclone had strengthened over the afternoon, and was now packing sustained winds of 165km/h, gusting as high as 235km/h.

It sat in roughly the same spot for much of Saturday, continuing to buffet Torba with strong winds and lashing the already saturated province with more rain.

"It's been sitting up north for almost two days and our fear is that it might continue to re-energise and intensify further," said Levu Antfalo, a senior meteorologist at the service. "It will probably hang around the north for another 24 hours. It's not good for that area."

The continued bad weather made it difficult for teams trying to assess the damage in Torba, particularly the worst-hit Torres groups of islands where houses had been toppled and food gardens destroyed.

The head of the National Disaster Management Office, Shadrack Welegtabit, said communication with the province was proving difficult, but some links had been established via VHF Radio and satellite phone.

He said the bad weather was slowing down attempts to gauge the extent of damage in the province of about 10,000 people.

"[Details] are still sketchy, we still need to get more," said Mr Welegtabit.

"In Torres you have five islands with people on them, so it's not really easy to get information. We need to get numbers from the other islands," an effort Mr Welegtabit said could take a couple of days at least.

A spokesperson for the Red Cross, Corinne Ambler, said her agency also had reports of extensive damage in Torres, including to water infrastructure.

"They're telling us that...quite a few of the houses have been damaged and some have been destroyed," she said. "There's about 1,000 in the affected area and I understand that almost 200 people are taking shelter in a cave on one of the islands."

On Sunday, the cyclone was forecast to bend to the south and travel towards New Caledonia.

There, the government announced that a cyclone "pre-warning" would take effect at 11pm, local time, on Saturday, with residents urged to prepare for the cyclone's arrival some time early next week.

In a statement, the civil security department said Donna was expected to bend its trajectory toward the territory, with wind and rain forecast to pick up from Sunday.

The pre-warning was not expected to have any effect on polling for the French presidential election in the territory on Sunday.

On its path towards New Caledonia, the cyclone would maintain its category four strength until Monday morning.

While it was expected to remain over the ocean to the west of Vanuatu's more populated islands, Mr Antfalo said most of the country should be prepared for strong winds and flash flooding.

"Severe weather conditions will prevail well into next week," he said.